The present invention relates to a gas-insulated switching device for an electric station such as a power plant and a switching station.
A well-known conventional gas-insulated switching apparatus is disclosed by Japanese Utility Model Right Publication No. H 03-39310 (1991). This gas-insulated switching apparatus is of a 1+xc2xd-switch arrangement in which oppositely-disposed parallel busbar connecting lines are arranged perpendicularly to the busbars. Busbar units of three phases constituting the main busbars are arranged almost in parallel in the side outer than the ends of the connecting lines.
To reduce the installation space of said gas-insulated switching device, for example, Japanese Application Patent Laid-Open Publication No. Hei 08-47125 discloses a vertically-placed breaker units which constitute the connecting lines. However, this configuration makes the gas-insulated switching device taller but less earthquake-resistant. Therefore, the gas-insulated switching device of this type may not be installed in a height-limited location. In other words, the gas-insulated switching device of this type is not available to an indoor plant or an underground substation.
A representative object of the present invention is to reduce the installation space without increasing its height.
The basic features of the present invention are that three horizontal breaker units are connected in series by the connecting lines each of which is disposed perpendicularly to the main oppositely-disposed busbars and that each of the mains has busbar units of three phases along a portion (stud) rising from the end of each busbar connecting line.
In the description of the present invention, the end of each busbar connecting line means the end of a circuit block near the main busbar in the breaker units which are located at both ends of the busbar connecting line. More concretely, it means the end of the enclosure of an airtight container constituting the power breaker block towards the main busbar. The horizontal power breaker unit is a power breaker unit whose airtight container constituting the power breaker block is placed horizontally, that is, the central axis of the airtight container is horizontal and electric contacts in the airtight container are horizontally separated.
The stud rising from the end of the busbar connecting line comprises a busbar connecting unit and is connected to the enclosure of the airtight container facing to the busbar. The busbar unit constituting the main busbar is placed oppositely to the main busbar of the busbar connecting unit or in the side of the main busbar connecting unit. A plurality of busbar connecting lines can be placed along the main busbar.
The present invention can suppress the physical height of the gas-insulated switching device as the busbar connecting lines are constituted by horizontal power breaker units. Further, the disposition of the busbar units along the studs which rise from the end of the busbar connecting lines can reduce the dimensions perpendicular to the main busbars of the gas-insulated switching device and consequently the installation space of the gas-insulated switching device.
For connection of the adjacent power breaker units, parts stand upright from the ends of the power breaker units. In other words, power breaker units are connected by a breaker connecting unit which comprises two vertical parts rising from the ends of the adjacent power breaker units and a horizontal part connecting these vertical parts. xe2x80x9cThe end of a power breaker unitxe2x80x9d means the end of the enclosure of the airtight container constituting the breaker block of the power breaker unit. Further, xe2x80x9cthe adjacent power breaker unitsxe2x80x9d means the adjoining two of three power breaker units which are connected in series.
In accordance with the present invention, the power breaker units are connected by means which rise upright from the end of the breaker units. In other words, the power breaker units are connected by a breaker connecting unit comprising vertical and horizontal units. Therefore, the distance between the adjacent power breaker units can be reduced. This can further reduce the installation space of the gas-insulated switching device.
Basically, a line leader line is vertically connected to a part (or a breaker connecting unit) between the adjacent power breaker units. Only one leader line is connected to one breaker connecting unit. In some cases (particularly when the leader line comprises a main and auxiliary lines), two leader lines can be connected thereto. In such a case, one of the vertically drawn-out leader lines is drawn out horizontally so as to be perpendicular to the other leader line. Or one of two leader lines is drawn out between respective busbar connecting lines. For example, one of the leader lines 35 for the first phase is drawn to a place between the first and second phases and one of the leader lines for the second and third phases are drawn to places between the second and third phases. There are two ways of drawing one of two leader lines away from the other leader line: drawing the leader line slantwise along the main busbar and drawing the leader line in parallel to the man busbar and then towards (perpendicular to) the main busbar.
In accordance with the present invention, when two leader lines are simultaneously drawn from the adjacent power breaker units or a breaker connecting unit, one of two vertically-drawn leader lines is drawn horizontally away from the other leader line or horizontally to a place between phases of the busbar connecting lines. Therefore, two leader lines can be simultaneously drawn from between the adjacent power breaker units. This can reduce the distance between two opposite busbars of the gas-insulated switching device.
Further, a transformer unit is connected to a portion between the adjacent power breaker units, or the stud of the breaker connecting units. To suppress the power breaker unit from increasing the physical height of the gas-insulated switching device, this invention disposes the transformer unit in a space between two studs on the ends of the enclosure of the airtight container which constitutes the breaker unit of the power breaker unit.